Anything by Mo Willems, love him!!! His retake on Golidlocks with the 3 Dinosaurs is cute, as is Leonardo the Terrible Monster.
Giraffes Can't Dance has been a fav of ours for a long time too.
Anything about feelings, such as When Sophie Gets Really Really Mad because it instigates a whole lotta conversation.
The whole Bear Snores On series.
Jan Brett books are on that list too. Love her illustrations.